Gas lift valve



W-:WQ 1968 l N. F. BROWN GAS LIFT 'VALVE Filed July 8. 1966 Fig.|

1544 j Isaak 3 Sheets-Sheet 1 Fig? Norrnon F. Brown www INVENTOR Oct l, '1968 N. F. BROWN l 3,403,694

GAS LIFT VALVE Filed July 8,1966 s sheets-sheet 2` 57 1567 /sss /6 00 FigZB INVENTOR Norman F. Brown Oct. l, 1968 N. F. BROWN 3,403,694

' GAS LIFT VALVE Filed July 8, 1966 3 Sheets-Sheet 3 INVENTOR Norman F. Brown BY www United States Patent O 3,403,694 GAS LIFT VALVE Norman F. Brown, Dallas, Tex., assiguor to Otis Engineering Corporation, Dallas, Tex., a corporation of Delaware Continuation-impart of application Ser. No. 556,594,

June 10, 1966. This application July 8, 1966, Ser.

22 Claims. (Cl. 137-155) This application is a continuation-in-part of my application entitled, Well Tools, Ser. No. 556,594, tiled June 10, 1966.

This invention relates to well tools and more particularly relates to ow control devices for use in wells.

It is one object of this invention to provide a new and improve-d well tool.

It is another object of this invention to provide a new and improved ow control device for use in a Well.

It is a further object of this inve-ntion to provide a new and improved gas lift valve for controlling uid ilow into a production tubing string supported in a well.

Itis still another object of the invention to provide a gas lift valve for controlling the introduction of lift gas from a well bore annulus around a production tubing string into the tubing string `for displacing well fluids within the tubing string to the sur-face end thereof.

It is a further object of the invention to provide a gas lift valve comprising flexible structure or articulated structure adapted to pass through a ow conductor having curved longitudinal portions.

It is another object of the invention to provide an articulated gas lift valve having an upper packing section, a central valve section, and a lower packing section.

It is a further object of the invention to provide a gas lift valve having pivotally interconnected longitudinal portions including a central valve portion, a lower packing portion, and an upper portion adapted to be connected with a locking mandrel provided with a packing assembly for sealing around the valve in a conduit above the valve portion.

It is still a 'further object of the invention to provide a gas lift valve having a valve portion of minimum length.

It is another object of the invention to provi-de a gas lift valve including a longitudinally movable valve assembly supported from an inner and an outer annular bellows each exposed on one side thereof to ambient pressure and on the other side thereof to a predetermined pressure of gas sealed within a dome chamber communicating with the bellows.

It is another object of the invention to provide a gas lift valve which is adaptable to operation responsive to an-v nulus pressure, tubing pressure, or a combination of such pressures.

It is another object of the invention to provide a gas lift valve including a spacer to provide a self-adjusting seat engaging portion of the valve.

It is another object of the invention to provide a spacer for adjusting the relative positions of components of apparatus comprising a member having a owable core.

It is another object of the invention to provide a method of forming a deformable spacer having a core of flowable material encased within a flexible covering.

It is still another object of the invention to provide an articulated gas lift valve having pivotal joints each including an external sleeve provided with maximum rigid sleeve support consistent with flexibility.

Additional objects and advantages of the invention will be readily apparent from the reading o-f the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

3,403,694 Paten-ted Oct. 1, 196,8y

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FIGURE 1 is a diagrammatic longitudinal view in section illustrating one form of gas lift valve embodying the invention releasably locked within a section of production tubing supported within a well casing;

FIGURES 2A and 2B taken together constitute a longitudinal view partially in section and partially in elevation of an articulated gas lift valve embodying the invention;

FIGURE 3 is an exploded perspective view of one of the universal joints between portions of the gas lift valve of FIGURES 2A and 2B;

FIGURE 3A is a view in elevation of the components of the universal joint of FIGURE 3 in their assembled relationship;

FIGURE 4 is an exploded perspective view of a check valve retainer in the gas lift valve of FIGURES 2A and FIGURE 5 is a fragmentary longitudinal view in section an-d elevation showing the gas lift valve at its open position;

FIGURE 6 is a fragmentary view in section and elevation of the upper end portion of a modified form of lift valve embodying the invention; and

FIGURE '7 is a longitudinal view in section and elevation of opposite end portions of another modified form of gas lift valve embodying the invention.

Referring to FIGURE 1, a gas lift valve 1500 embodying the invention is secured on a locking mandrel C which is Ireleasably locked in a production tubing string D. 'The tubing string is supported within a well casing E providing an annulus F :between the tubing string and the well casing for conducting lift gas to the gas lift valve for displacing well fluids in the tubing string to the surface.

The tubing string includes a landing nipple G connected between pipe joints H of the production tubing string by upper and lower internally threaded couplings I. The landing nipple has a plurality of ports Ga located between upper and lower reduced 'bore portions Gb and Gc, respectively, which provide seating surfaces for packing assemblies above and below the ports. The nipple ports provide fluid communication between the bore of the nipple and the annular space F for carrying out various well operations including allowing lift gas to flow from the annulus F into the tubing string. The upper and lower reduced bore portions of the landing nipple receive packing assemblies connected on the gas lift valve for providing a uid seal around the valve above and below the ports Ga. The landing nipple also includes internal annular locking recesses Gd and Ge which receive locking dogs Ca on the locking mandrel supporting the gas lift valve.

The landing nipple C may conveniently comprise a Type X Otis Locking Mandrel, or a modified form thereof, as illustrated Vat page 3662 of the Composite Catalogue of Oil Field Equipment and Services l1964-65 edition, published lby World Oil, Houston, Tex. Since the gas lift valve 1500 has its own upper packing, the Type X Locking Mandrel may be modified by removing its packing and reducing the length of its lower. end portion so that the mandrel is threadedly engaged in the upper end portion of the gas lift valve 1500 shown in FIGURE 2A.

As illustrated in FIGURES 2A and 2B, the gas lift valve 1500 is an articulated assembly having an upper packing section 1520, a central valve section 1521, and a lower packing section 1522.

The upper packing section 1520 includes a mandrel 1534 provided with an internally threaded upper end portion 1534a to permit connection of the upper end'of the gas lift valve with its locking mandrel C. A suitable extern-al annular packing 1536 is supported on the mandrel 1534between an upper retainer ring 1537 threaded on the mandrel and held against rotation by a lock pin 1538 and a lower retainer ring 1539 telescoped downwardly over a split lock ring 1540 positioned within an external annular locking recess 1541 of the mandrel 1534.

The upper packing section 1520' is connected with the valve section 1521 by a universal joint 1542 enclosed Within a flexible tubular sleeve 1543. The universal joint, FIGURES 3 and 3A, includes a swivel crosshead 1542a connected within and between two pairs of identical oppositely positioned intermeshed spiders 1544, each of which has an extern-al annular recess portion 1545a for receiving a portion of the flexible sleeve to facilitate sealing around the joint by the sleeve. Each of the spiders has an internal arcuate flange portion 1545. The flange portions 1545 of the upper pair of spiders are received within an external annular recess 1546, FIGURE 2A, around the lower end portion of the packing assembly mandrel 1534. Each of the spiders 1544 comprises a half cylinder shaped body flange portion 1544a on which the internal flange portions 1545 are formed and an integral arcuate finger portion 1544b provided with a centrally positioned circular hole 1544e. Each finger portion 1544b has an internal spherical surface portion 1544d which substantially conforms to the contour of the outer wall surface of the crosshead. Each finger portion 1544b also has vertical substantially flat edge surfaces 1544e and end edge surfaces 1544f which join along the centerline of the finger portion sloping :slightly toward the body of the finger portion providing an end face of tapered, slightly convex, configuration. The outer surface of each finger portion has a cylindrical surface portion 1544g extending from the arcuate recess 2545a to a chamfered or relieved surface portion 1544h which extends to the end edge surfaces 1544f. Each finger portion also has a small triangular shaped corner edge surface 1544i extending between the surface portions 1544g and 154417 and the edge surface 1544e. The corner edge surface 1544i facilitates pivotal movement of the spider within the tightly fitting sleeve 1543 and minimizes possible internal surface damage to the sleeve which might be effected by a sharp corner edge surface.

The swivel crosshead 1542a comprises a ring member 1542b having four radially and outwardly extending round lugs 15421: evenly `spaced at 90 degree intervals around the ring member. The outer spherical surface portion 1542d of the ring member substantially mates with the internal spherical surface portion 1544d of the finger section on each spider member. The two upper spiders are fitted on opposite sides of the swivel crosshead and with opposite lugs 1542s` each received within the hole 1544c of a spider. The finger portions of the two upper spiders extend downwardly. The adjacent end edge surfaces 1544]' of the flange portions 1544a are slightly spaced apart when the spide-rs are on the crosshead, FIGURE 3A. The two lower spiders are also positioned on opposite sides of the swivel crosshead spaced.90 degrees-.from the upper spider set with the finger portions of the lower spider set extending upwardly and received between the oppositely positioned downwardly extending finger portions of the upper spider slot. The upper spiders thus pivot about one axis extending through a pair of opposite lugs 1542c -while the lower spiders pivot about an axis 90 degrees removed through the other set of opposite lugs 15426.

Each spider finger portion 1544b encircles or encompasses slightly less than 90 degrees of the crosshead 1542a so that ample clearance is provided between adjacent vertical finger portion edge surfaces 1544e to permit a desired predetermined degree of pivotal movement of each set of spiders relative to the crosshead while providing maximum solid back-up for the flexible sleeve 1543 `consistent with the flexibility desired. Also it may be seen in FIGURE 3A that substantial clearance is provided between the end surfaces 1544)c On each spider and the portion of the flange portions 1544a of the adjacent oppositely directed spiders to also permit the de'- sired movement of the spiders without structural interference between spiders. In articulated gas lift valves in accordance with the invention the clearances between adjacent spider surfaces are sized to permit at least seven degrees of pivotal movement between connected portions, such as between the upper packing section 1520 and the valve section 1521.

Since the upper spiders are clamped on the lower end portion of the upper packing assembly mandrel 1534, the upper packing assembly is movable relative to the crosshead about one axis and the Valve section 1521 supported from the lower spiders is movable relative to the crosshead about an axis degrees spaced from the packing mandrel pivotal axis. Universal joint action is therefore provided between the upper packing section and valve section of the gas lift valve whereby curved longitudinal portions of a flow conduit are readily traversed.

An upper end portion 1543a of the flexible sleeve 1543 is telescoped over the packing assembly mandrel extending upwardly to a position adjacent to the retainer ring 1539 clamped on the mandrel by a tubular compression sleeve 1547 placed over the upper end portion of the flexible sleeve and contracted as by crimping annular rolled grooves 1547a which aid in holding the compression sleeve on the flexible sleeve. The flexible sleeve serves the dual purpose of locking the universal joint spiders 1544 at their respective assembled positions on the swivel Icrosshead and, assisted by the application of a suitable adhesive sealant, such as Larkin epoxy cement, on its inner faces prevents leakage of gas from the exterior of the valve to its central flow passage.

The valve section 1521 of the gas lift valve includes an inner bellows assembly 1548, an outer bellows assembly 1549 telescopically engaged over the inner bellows assembly, and a dome chamber assembly 1550 telescoped along its lower end section over an upper end section of the outer bellows assembly. The inner bellows assembly includes an upper tubular mandrel 1551 which is provided along its upper end section with external annular longitudinally spaced flanges 1552 and 1553 defining an external annular recess 1554 which receives the arcuate internal flanges sections 1545 on the two lower spider members 1544 of the universal joint 1542. The mandrel 1551 is enlarged along a lower end section 1555 which is externally threaded and provided with a longitudinally extending external recess 1556 along its threaded section to conduct dome gas, as explained hereinafter. An internal sleeve 1557 is slidably fitted telescopically into the enlarged lower end section 1555 of the mandrel 1 and is provided with an external annular flange 1558. A longitudinally contractable and extendable inner bellows 1559, formed of a material such as metal, is secured around its upper end to the lower end of the enlarged section 1555 of the ymandrel 1551 and around its lower end to the upper face of the flange 1558 on the sleeve 1557. The bellows extends and contracts as the sleeve 1557 telescopes into and out of the lower end of the mandrel 1551. The outer bellows assembly 1549 includes a tubular mandrel 1560 having an internally threaded upper end section secured on the enlarged lower end section 1555 of the upper mandrel 1551. The mandrel 1560 has an externally threaded reduced lower end section 1562 provided with an internal annular lower end flange 1563 which fits in sliding relationship over the sleeve 1557 below its external annular flange 1558. A longitudinally expandable and contractable outer bellows 156301 which may be formed of a suitable material such as metal, is secured around its upper end to the lower face of the flange 1563. A valve ring 1564 is fitted telescopically over a lower end section of the sleeve 1557 and secured around its upper end face to the lower end of the bellows 1563. The ring 1564 has a reduced lower end section 1565 which is substantially the same diameter as the sleeve 1557 and provides an upwardly facing internal annular shoulder 1566 which is engageable with the lower end of the sleeve 1557. The valve ring is suitably Secured, as by sliver soldering around an annular groove 1567, to the sleeve 1557.

The dome chamber assembly 1550 includes a tubular body section 1568 having an upper reduced end section 1569 provided with an internal annular upper end flange 1570 which fits over the fiange 1553 on the mandrel 1551 and is sealed thereto as by silver soldering around an annular groove 1571 in the ange 1570. A lower end section of the flexible sleeve 1543 fits telescopically over the reduced upper end section 1569 of the member 1568 and is secured thereon by the lower compression sleeve 1547 which is annularly crimped in the same manner as the upper compression sleeve 1547, assisted by cement, to secure the lower end section of the compression sleeve in sealed relationship around the liexible sleeve over the upper end section of the member 1568. A lower slightly reduced end section 1572 fits over the upper reduced end section 1561 of outer bellows mandrel 1560 and is sealed thereto as by silver soldering around annular grooves 1573 within the section 1572. A radially spaced concentric relationship between the tubular member 1568 and the tubular mandrel 1551 provides an annular dome chamber 1574 for dome gas employed to bias the gas lift valve downwardly toward a closed position. A plug member 1575 secured in the tubular member 1568 is provided with internal threaded bore 1576 reduced in diameter along its lower end section 157611 and opening through the inward end opening into the dome chamber for the introduction of dome gas. The bore of the plug member is closable by a threaded removable core 1577. A gasket 1577a seals between the inward end of the core and the plug member 1575 in the bore section 1576a.

A tubular Valve body 1578 is threaded along an upper end section over the lower end section 1562 of the outer bellows mandrel 1560.A ring seal 1579 in an external annular recess in the bellows mandrel 1560 seals between the bellows mandrel and the upper end section of the valve body. The valve body has a plurality of longitudinally spaced lateral slots 1580 to admit lift gas into the valve. The valve body 157 8 is reduced along a lower end section 1581 providing an extern-al downwardly facing annular shoulder 1581a and an internal upwardly facing annular shoulder 1581b below the slots 1580.

A tubular valve seat member 1582 is supported concentrically within the valve body 1578. The valve seat member has an enlarged lower end section 1583 received within the reduced lower end section 1581 of the valve body. A ring seal 1584 positioned within an external annular recess around the enlarged section of the valve seat member seals between the valve body and valve seat member. An annular split retainer member 1585 is supported in concentric relationship around the valve seat member 1582 within the tubular valve body 1578 along its slots 1580 for retaining a flexible annular sleeve type check valve 1586 clamped along a lower end section between the retainer and the valve seat member. The retainer,

FIGURE 4, is a split annular member having a lower end internal annular flange 1587 and is outwardly flared or outwardly and upwardly divergent along its upper end section 1588 which comprises a plurality of circumferentially spaced upwardly and divergently extending fingers 1588 defining a plurality of upwardly opening slots 1589 through which lift gas flows into the valve from the valve body slots 1580. The side edge surfaces 1590 on the head ends of the fingers 1588 engage the inner surface defining the bore through the valve body 1578 above its slots 1580 providing radial support for the fingers. The internal flange 1587 of the retainer is received within an external annular recess 1591 of the valve member at the upper end of its enlarged section 1583 while the lower end surface of the retainer fiange engages the internal annular shoulder 1581b of the valve body 1578 so that the retainer is clamped between the valve seat member and the valve body and holds the valve seat member 'against downward movement within and relative to the valve body 1578.

The flexible check valve 1586 is tightly clamped along its lower end section 1592 between the retainer 1585 and the valve seat member with an internal annullar portion lof the check valve being squeezed into an external annular recess 1593 to aid in holding the check valve in position between the retainer and valve seat. An upper free-end portion 1593 of the check valve element is expandable and contractable between the external surface of the valve seat member and the internal edge surface 1594 of the lingers on the retainer 1585. The valve element 1586 functions as a check valve to prevent back flow from within the vailve outwardly through the lateral slots 1580. Outward flow past the check valve element toward the slots 1580 biases the upper free end section of the check valve radially outwardly into seated relationship over the inside edges 1594 of the fingers 1588 thereby shutting off ow from within the valve into the slots 1589 `between the fingers 1588. The upper free end section 1583 of the check valve extends above the fingers 1588 sufficiently to seat also on the inside surface of the valve body 1578 above the fingers. Flow into the valve through the slots 1580 passes through the slots 1589 between the fingers collapsing the check valve inwardly as shown in FIGURE 5 so that the check valve permits flow into the gas lift valve but prevents fiow outwardly from within the valve.

The valve seat member 1582 has an upper outwardly divergent or ared end section 1595 which is concentrically positioned within and spaced apart from the surface defining the bore through the valve body 1578 to permit ow around the valve seat member within the bore of the valve body. The outside surface of the valve member along its upper end section provides an inside support for the check valve element when it is contracted inwardly to permit upward iiuid flow through the valve around the valve seat member. The valve member has an annular upper end seat lsurface 1596 which is engageable by an annular valve face member 1597 which is supported within and longitudinally movable with the valve ring 1564 of the outer bellows assembly between the engaging closed relationship of FIGURE 2B and the spaced, open relationship of FIGURE 5. The valve face member is supported around the reduced end section 1565 of the valve ring 1564 by an annular retainer sleeve 1598 the outer surface of which is slidable within the bore of the valve body 1578. A retaining wire 1599 is confined lbetween the upper end section of the retainer 1598 and the valve ring 1564 to secure the retainer on the valve ring. The retaining wire is inserted into its recess in the retainer through a tangential slot in the retainer opening into the wire recess.

An annular spacer or back-up member 1600 is positioned around the section 1565 of the valve ring 1564 within the retainer 1598 between the top s-urface of the valve face member 1597 and the enlarged upper end section of the valve ring. The spacer 1600 is especially adapted to permit precision fitting of the valve face member 1597 with the upper end seat surface 1596 on the seat member 1582 after assembly of the gas lift valve. The spacer comprises a ring shaped core 1601 of a low melting point metal encased within a covering 1602 of a suitable rubber or plastic which resists the chemical action and operating temperatures of the fluids, such as oil and gas, to which the member is exposed. For example, the core 1601 may be formed of a metal such as bismuth alloy sold under the trademark Cerrolow-l36 which has a melting point of about 136 degrees F. The spacer" is manufactured by forming an lannular ring of the low melting point metal at a temperature below its melting point, wrapping the core with the uncured outer coating material and suitably curing the coating material as by pressure and heat to form the impermeable flexible covering 1602 encasing the core. The casing is preferably formed by the iiexible material in the form of a cord or string which is tightly wound around the core so that during the curing and until the casing material is melted into a continuous sheath, the metal core which may be heated above its melting point will remain confined within the casing material.

The spacer 1600 may 'also be formed in a number of other similar ways. For example, a core of water or similar liquid is frozen, the frozen core is wound with uncured rubber, and the wound core is then placed in a mold to cure under both pressure and heat binding the outer casing or coating material together forming an impermeable flexible covering around the core. The core melts transforming it to the liquid state permitting the spacer to be readily deformed. The core may also comprise a low durometer rubber containing no curing agents so that after the outer coating is cured under heat and pressure the core will remain a soft owable material. The core may comprise wax which is covered and treated under heat and pressure as previously described. Other cores may comprise: granular materials, such as very fine glass beads, bound together by a continuous phase of wax; an oil filled hollow rubber tube; or a rubber tube infiated with a low freezing point liquid such as mercury.

The spacer 1600 performs a basic function of adjusting the relationship between the seat member 1597 and the surface 1596 on the valve seat member after the valve section 1521 of the gas lift valve is completely assembled. The valve assembly is heated to a temperature above the melting point of the low melting point metal core 1601 of the spacer so that the solid core is transformed to the liquid state. With its core liquid, the deformability of the spacer is appreciably increased. The valve is biased toward its closed position as by injection of dome gas into the dome chamber 1574. With the spacer in the semifiuid state the seat member 1597 assumes an optimum seated relationship with the seat surface 1596 and the spacer, due to its deformability, conforms to the shape of the space between the seat member and the enlarged section of the valve ring around the valve ring within the sleeve 1598. With the spacer so conformed to the proper shape to allow the seat member to assume full-seated engagement with the seat surface On the valve seat member, the temperature of the valve assembly is reduced allowing the core of the spacer element to return to its solid state in a shape which permits the components of the valve to lit such as to provide optimum engagement between the valve face member 1597 and the valve seat surface 1596 on the valve seat member 1582. It will be seen that the spacer may be adjusted simply by heating the valve assembly at any time disassembly and reassembly of the valve is required for parts replacement or repair. When assembled, the spacer 1600 is virtually incompressible.

The following valve components are movable longitudinally as an assembly or unit for positioning the valve face member 1597 between its open and closed positions relative to the upper seat surface 1596 of the valve member 1582: the valve seat member 1597, the retainer 1598, the spacer 1600, the valve ring 1564, the inner valve sleeve 1557 and the lower ends of both bellows 1559 and 1563a. During upward movement of these components as a unit, the inner sleeve 1557 telescopes into the mandrel lower end section 1555 while the inner and outer bellows 1559 and 1563, respectively, are compressed. Conversely group of components moves downwardly as a unit to position the face member 1597 in closed relationship with the seat surface 1596 while the bellows 1559 and 1563 are expanding. The dome gas chamber effectively includes the space around the sleeve 1557 within the outer bellows 1564 and the space around the inner bellows 1559 within the mandrel 1560 and the gas passages 1556. Dome gas may fiow from `the chamber 1574 through the longitudinal slots or flow passages 1556 formed along the threads1561 around the inner `bellows 1559 within the mandrel 1562, past the flange 1563 around the sleeve 1557, within the 8 outer bellows 1563a, and along the surface of the sleeve 1557 to the joint 1567 within the Valve ring 1564.

The lower seal assembly section 1522 of the gas lift valve is pivotally connected with the valve section 1521 by a lower universal joint 1542 which is identical to the previously described upper universal joint including a swivel crosshead 1542a with two pairs of spiders 1544. The 'arcuate internal flange portions 1545 of the upper set of spider' members 1544 are received within an external annular recess 1603 in the lower end section 1583 of the valve seat mem-ber 1582. The spider members function not only as a part of the universal joint 1542 between the valve and lower packing assembly sections but also their upper end surfaces are engageable with the lower end surface of the valve body 1578 holding the valve seat member against upward movement relative to the valve body.

The lower packing assembly has a tubular mandrel 1604 provided with a reduced upper end section 1605 having an external annular recess 1606 which receives the flanges 1545 on the lower set of spiders 1544 of a lower universal joint 1542 identical to the upper joint. The joint 1542 is covered to make it fiuidtight and its spider members are held on the crosshead 1542a and the valve seat member and seal assembly mandrel, respectively, by a lower flexible sleeve 1543 confined around the reduced lower end section 1531 of the valve body 1578 by the crimped compression sleeve 1547. The lower end section of the flexible sleeve is similarly secured on the mandrel 1604 by another crimped compression sleeve 1547. A lower packing 1536, identical to the upper packing element 1536, is supported on the mandrel 1604 below an upper retainer ring 1539 which is held against upward movement on the mandrel by a split lock ring 1540 received in an external annular recess 1607 of the mandrel 1604. The packing is limited against downward movement on the mandrel by the annular rings 1608 threaded on the lower reduced threaded end section 1610 of the mandrel 1604.

The gas lift valve 1500 is used in a well known type of gas lift system where a fluid such as gas is pumped in a well bore through an annular flow passage around a production tubing string and well fluids `are displaced to the surface through the tubing string by the lift fluids which are admitted into the tubing string by the gas lift valve. The gas lift valve is operable responsive to the pressure within its central bore, the pressure around the valve, or a combination of such pressures depending upon design. Prior to installation of the valve its dome chamber 1574 is charged with gas introduced through the bore of the plug 1575 and sealed therein by engagement of the core 1577 within the threaded section of the bore of the plug. The dome gas is introduced into the chamber until its pressure within the chamber is at a desired predetermined value to Icontrol the opening pressure of the valve. The dome gas introduced into the dome chamber flows downwardly through the longitudinal flow passage 1556 formed in the threaded section 1555 of the mandrel 1551, around the mandrel 1557 within the mandrel 1562 around the inner bellows 1559, around the tubular member l1557 within the ange 1563 into the outer bellows :1564 so that the dome chamber effectively extends downward around the inner bellows mandrel and the tube 1557 within the outer bellows to the solder joint 1567. The pressure of the dome gas is effective over an annular area determined by the difference between the areas of circles having diameters equal, respectively, to the mean effective diameters of the bellows and since the outer bellows is larger than the inner and below the inner bellows, the valve sleeve 1557, the member 1597 and related components are biased downwardly by a force determined iby this annular area difference times the dome pressure excess over the ambient pressure. The force tending to bias the valve upwardly toward the open position is determined by the same annular area difference multiplied by the ambient pressure excess over the dome pressure. When the valve is open, one ambient pressure, 'with an excess over the dome pressure, holds the valve in the open position until it diminishes to less than the dome pressure. When the valve is closed, however, the downwardly exposed annular area difference between the areas of the mean effective diameters of the two bellows, and hereinafter referred to as the bellows area, is divided into two components at the diameter of the mean effective line of seal in the interface between the lower end face of the valve member 1597 and the valve seat 1596, hereinafter referred to simply as the valve diameter.

The bellows area has fixed inner and outer diameters and the valve diameter can be varied las by interchange of valve elements 1582 while the lower face of the member 1597 is wide enough to accommodate a satisfactory variety of valve diameters.

When the gas lift valve is in operation, the operating gas pressure outside the valve and the pressure of fiuids inside the bore of the valve are independently variable. If the Valve diameter is midway between the inner and outer diameters of the bellows area, the operating gas pressure 'would act on that part 0f the bellows area lying outside the valve diameter and the tubing pressure would act on the remainder lying inside it. The valve opening fforce would be the sum of these two force components, but after the valve is opened, the two pressures equalize.

If the valve diameter approaches the inner diameter of the bellows area, the operation of the gas lift valve becomes almost wholly a function of the operating gas pressure and independent of the fiuid pressure in the tubing. Conversely, if the valve diameter approaches the outer diameter of the bellows area, operation becomes almost wholly a function of the fluid pressure in the tubing independent of the operating gas pressure.

By placing the valve diameter anywhere between these two extremes any proportion of infiuence from the two variable factors can be selected.

It will also be seen that if there exists, as is usual, an appreciable disparity between the two pressures, the valve opening force, which is the sum off two component forces at the moment of opening, may increase to a larger -force after the valve is opened when the larger of the two pressures becomes effective over the whole of the bellows area. This entails an appreciable drop in operating pressure before the valve can be `closed again by its dome pressure and this difference between the opening and the closing pressures of the valve is the effect known as the spread of the valve.

The check valve element 1'592 prevents back fiow of uids from within the central bore of the valve out- Iwardly from the valve through its lateral ports 1580. Any fiow toward the ports -1580 expands the upper end section 1593 of the check valve outwardly against the inside edges of the fingers of the seat member 1585 shutting off fiow through the longitudinal slots defined between the fingers of the member.

The gas lift valve 1500 when supported from a type X Otis Locking Mandrel is installed in its landing nipple by use of conventional wireline equipment provided with a type X Otis Running Tool illustrated and dcribed at page 3744 of the Composite Catalogue of Oil Field Equipment and Services, supra. The 'gas lift valve is removed from its landing nipple through the production tubing string utilizing the same wireline equipment with a type GR Otis Pulling Tool illustrated at page 3746 of the Composite Catalogue of Oil Field Equipment and Services, supra.

It will now be seen that a new and improved well tool has been described and illustrated.

It Iwill be further seen that a new and improved fiow control device for use in a well has been described and illustrated.

It will also be seen that a new and improved gas lift valve for controlling fluid fiow into a production tubing string of a well has been described and illustrated.

It will be further seen that the gas lift valve controls the introduction of lift gas from a well bore annulus into a production tubing string in the well bore.

It will be further seen that the gas lift valve is an articulated structure adapted to pass through a flow conductor having curved longitudinal portions.

It will be further seen that the gas lift valve includes a central valve section, an upper packing section, and a lower packing section.

It will be further seen that the upper, lower, and central sections of the valve are pivotally interconnected.

It will also be seen that the universal joint connections between the gas lift valve sections include a flexible outer sleeve over assembled crosshead and spider members providing optimum substantially rigid support or back-up for the fiexible sleeve.

It will also be seen that the valve section of the gas lift valve includes a longitudinally movable valve assembly supported from an inner and an outer annular bellows exposed on one side to ambient tubing and/or annulus pressure and on the other side to a predetermined dome gas pressure from a sealed dome chamber communicating with the bellows.

It will be further seen that the gas lift valve includes a spacer member providing a self-adjusting valve seat engaging member permitting optimum adjustment of the relationship between the components of the valve section.

It will be further seen that the spacer member includes a core of fiowable material encased within a covering of flexible material.

It will be further seen that a method of forming a spacer for adjusting relative positions of components of an apparatus comprises forming a core of a liowable material, reducing the temperature of the core material until it is in its solid state, wrapping the core material with uncured rubber, and subjecting the wrapped core to heat and pressure until the rubber is cured to form an impermeable flexible covering around the core.

It will be further seen that the gas lift valve is readily modified to permit it to operate responsive to well annulus pressure, production tubing string pressure, or a combination of such pressures.

' Illustrated in FIGURE 6 is the upper end portion of a modified form of a gas lift valve 1500A which is supportable by the previously discussed type X Otis Locking Mandrel without modification. The valve 1500A is identical in all respects to the gas lift valve 1500 except that the valve 1500A does not include an upper packing assembly section. The function of the upper packing assembly section is discharged by the packing on the type X Locking Mandrel. Referring to FIGURE 6, an upper connector member 1700 coupled directly with the upper universal joint 1542 is internally threaded for direct assembly on the lower threaded end portion of the type X Locking Mandrel. The connector has an external annular lower end recess 1701 which receives the internal flange portions 1545 on the upper spider members 1544 of the universal joint. The upper end portion 154311 of the flexible sleeve 1543 extends upwardly over a substantial portion of the connector 1700 and is secured around the connector by a compression sleeve 1547, as previously described in connection with the gas lift valve 1500. The connector 1700 thus is pivotally connected with the upper universal joint in the same manner as the upper packing section 1520 of the valve 1500 so that the valve 1500A, while not having its own upper packing section, is a three section articulated structure. By the elimination of its upper packing section it will be obvious, however, that the valve 1500A must be used with a locking mandrel having its own packing, such as an unmodified form of the previously discussed type X Otis Locking Mandrel. The gas lift valve 1500A is installed and removed and functions in all respects identically to the valve 1500.

It will thus be seen that a modified form of a gas lift valve embodying the invention comprises an articulated structure including a central valve section, a lower packing section, and an upper connector member adapted to be directly coupled to a locking mandrel having a packing assembly.

It will be further seen that the modified form of gas lift valve has an upper retainer member which is directly coupled with the upper universal joint of the valve.

A still further modified form of gas lift valve 150GB embodying the invention is illustrated in FIGURE 7. The valve 1500B is a nonarticulated or substantially rigid structure providing a valve of minimum longitudinal length which basically comprises a modified form of the central valve portion of the valves 1500 and 1500A while eliminating the pivotally connected end packing sections of these valves.

In FIGURE 7 the same reference numerals are ernployed as in FIGURES 2A, 2B, and 5 for those valve components which correspond identically with components of the valve 1500 while modified components serving essentially the same function as in the valve 1500 are denoted by the reference numerals used in the FIGURES 2A, 2B, and 5 with the postscript a added. The upper end portion 1557b of the sleeve 1557a is internally threaded for the connection of a locking mandrel, such as the type X Otis Locking Mandrel, and is externally threaded along a section 1557c. The tubular body portion 1568er, the inner surface of which defines the outer wall of the annular dome chamber 1574, is sealed around the upper end sleeve portion 1557b as by soldering around an annular groove 1557d. A pair of retainer rings 1557'e are threaded on the sleeve section 1557s against the upper end face of the tubular body valve body section 1568a.

The tubular Valve seat member 1582a, which corresponds with the valve seat member 1582 of the lift valve 1500, is threaded along its lower end portion 1582!). A ring seal S2c in an external annular recess 1582b around the valve seat member seals between the valve seat member and a lower end portion of the tubular valve body 1578a. A retainer ring 1709 is threaded on the valve seat member portion 1532b against the lower end face of the sleeve portion 1578a. All of the central structure of the valve 1500B which is not illustrated in FIG- URE 7 is identical to the valve section of the gas lift valve 1500. A lower packing mandrel 1710 having an enlarged upper end portion 1711 is threaded on the lower end portion 1582b of the valve seat body. An annular packing 1712 is supported on the packing mandrel by retainer rings 1713 threaded on the packing mandrel against the lower end face of the packing. The packing is held against upward movement on the mandrel by its external downwardly facing annular V-shaped groove 1714. The packing mandrel is threaded along a lower reduced end section 1715 for the connection of structure such as a section of tubing below the gas lift valve.

The gas lift valve 1500B functions in exactly the same manner as the gas lift valve 1500, and, in view of the absence of the pivotally connected upper and lower end sections together with the employment of the inner and outer bellows structure, provides a Valve which is quite short in length. The valve may be supported within a landing nipple, such as the landing nipple G shown in FIGURE l, from a standard type X Otis Locking Mandrel. The valve is installed and removed with conventional wireline apparatus utilizing standard running and pulling tools, as previously discussed.

It will now be seen that a modified form of gas lift valve embodying the invention is a nonarticulated structure of minimum length.

It will be further seen that the nonarticulated or substantially rigid form of gas lift valve includes an upper connector portion for securing to `a locking mandrel and a lower packing assembly portion.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well tool comprising: body means having a central bore therethrough and lateral port means communicating with said bore; valve seat means supported in said body means; valve means movably supported in said body means and adapted to coact with said seat means for controlling fluid flow into said central bore from said port means, pressure responsive means connected between said body means and said valve means for movably supporting said valve means within said body means, said valve means including self-adjusting spacer means for aligning a valve seat engaging face member of said valve means relative to said valve seat means, said spacer means including a flowable core p0rtion and a covering whereby said spacer means is deformable to adjust the position of said valve seat engaging face member to obtain optimum engaging relationship between said face member and said valve seat means, said core comprising a low melting point metal and said covering comprises rubber wrapped about said core While said core is maintained below its melting point and said spacer is then subjected to heat and pressure, thereby binding said rubber together forming an impermeable fiexible covering around said core.

2. A well tool in accordance with claim 1, wherein said pressure responsive means comprises a first bellows and a second bellows each connected at a first end with said body means and at a second end with said valve means.

3. A well tool as defined in claim 1 wherein said pressure responsive means comprises an inner bellows and an outer bellows each connected at a first end with said body means and at a second end with said valve means.

4. A well tool as defined in claim 1 wherein said body means comprises an articulated structure having a central valve portion and pivotally connected upper and lower portions secured therewith.

5. A well tool as defined in claim 4 wherein said upper and lower portions of said body means are each connected with said central portion of said body means by universal joint means comprising a circular swivel crosshead having radial outwardly extending lugs, upper and lower spider members supported on said lugs, finger portions of said spider members inter-meshing around said crosshead to provide rigid substantially solid support structure for an enclosing flexible sleeve, and a tubular liexible sleeve secured in substantial fiuidtight relation over said crosshead and spider members extending above and below said upper and lower spider members.

6. A well tool as defined in claim 5, wherein said body means includes an annular chamber adapted to be charged with a fluid under pressure and sealed, said annular chamber communicating with said valve means and said pressure responsive means for biasing said valve means toward said seat means.

7. A well tool as defined in claim 1, wherein said pressure responsive means comprises an inner bellows and an outer bellows each secured at a first end to said valve means and secured at a secon-d end to said body means, and said body means includes an annular chamber adapted to be charged with a fiuid under pressure and sealed, said chamber communicating with one side of said valve means and each of said bellows for biasing said valve means toward said seat means.

8. A well tool as defined in claim 7 including check valve means for preventing flow of fluid from said central bore through said body means outwardly through said lateral port means in said body means.

9. A gas lift valve for admitting fluid within a well bore into a central flow passage through said valve to admit said fluid into a tubing string connected with said valve comprising: a tubular body having a longitudinal bore therethrough, said body including concentrically positioned inner and outer tubular members providing an annular chamber adapted to be charged with a fluid under pressure and sealed, said tubular body having lateral port means for communicating said bore with the exterior of said body; an annular valve seat member concentrically secured within said body, said valve seat member having an annular seat surface thereon; an annular valve assembly concentricallyv positioned Within said body and adapted to move longitudinally therein, said valve assembly including a valve face member having an annular face adapted to engage said annular seat surface on said valve seat member when said valve assembly is at one longitudinal end position to prevent iiuid flow between said central bore and said central bore and said lateral port means, and a spacer member supported between a face of said valve face member and a shoulder surface of said valve assembly and adapted to deform for maintaining alignment between said valve face member and said valve seat member for optimum engagement between said members; a first annular bellows adapted to be longitudinally extended and compressed secured at a first end with said inner tubular member of said body defining an inner wall portion of said annular dome gas chamber and secured at a lsecond end thereof with said valve assembly; and a second annular bellows secured at a first end thereof with an outer tubular member of saidn body defining a portion of an outer wall of said dome gas chamber and secured at a second end thereof with said valve assembly, said bellows supporting said valve assembly whereby said assembly is biased toward said valve seat member by fluid pressure within said dome gas chamber, said spacer means comprising an annular ring-shaped 'member comprising a core flowable under predetermined conditions having a flexible covering.

10. A gas lift valve as defined in claim 9, including an annular flexible check valve member confined between said valve seat member and said body to prevent flow of fluid from said central bore through said lateral port means to the exterior of said body.

11. A gas lift valve as defined in claim wherein said valve assembly is biased toward closed position engagement with said valve seat member by pressure of fluid in said dome gas chamber applied over an effective annular area difference between the areas of the mean effective diameters of said first and said second bellows and said valve assembly is biased toward open position by ambient pressure around said valve assembly other than said dome gas pressure applied over said annular area difference.

12. A gas lift valve as defined in claim 9, including a lower external annular packing on said body below said lateral port means.

13. A gas lift valve as defined in claim 9, wherein said body comprises yan articulated structure including upper, middle, and lower Sections pivotally interconnected.

14. A gas lift valve as defined in claim 13 including an external annular packing on said lower body section.

15. A gas lift valve as defined in claim 14 including an external annular packing on said upper section of said body.

16. A gas lift valve adapted to be connected in a tubing string for controlling tiuid flow from a well bore annulus into said tubing string comprising: a tubular body having a central longitudinal bore therethrough and including concentric spaced tubular members defining a dome gas chamber therebetween adapted to be charged with fluid under pressure and sealed; said tubular body having lateral port means for communicating the exterior of said body with said central bore; a tubular valve seat member secured concentrically within said body and having an upper annular seat-surface spaced apart within said body; a tubular valve assembly concentrically and movably supported within said body, said valveassembly having an upper end portion telescopically slidable within a lower end portion of an inner tubular member of said body and an annular valve member supported Within said valve assembly having a valve face adapted to engage said annular face on said valve seat member when said valve assembly isat an end position for preventing iluid flow between said lateral portmeans and said central bore of said body, and an annular spacer member supported between a face of said valve member and a face on another component of said valve assembly for maintaining optimum alignment of said spacer member relative to said valve seat member annular face; a first inner annular bellows secured around a first end thereof with an end surface of an inner tubular member of said body and secured at a second end thereof with a flange surface on said valve assembly; a second annular bellows secured at a first end thereof with an annular surface on one outer tubular member of said body and secured at a second end thereof with a ange surface of said valve assembly, said iirst and second bellows being extendable and compressible longitudinally to permit said valve assembly to move relative to said valve seat member for opening and closing said valve; an external wall surface portion of said valve assembly, an external surface of said inner bellows, and internal surface of said outer bellows comprising wall portions of said dome gas chamber whereby fluid under pressure in said dome gas chamber biases said valve assembly toward said valve seat member; other wall portions of said valve assembly, internal wall surface portions of said inner bellows and the external wall surface portions of said outer bellows being in communication with fluid pressure within said body for biasing said valve assembly away from said valve seat member toward open position; a slotted annular retainer member concentrically secured between said valve seat member and said external tubular assembly of said body along said lateral ports of said body; and an annular flexible check valve concentrically clamped between said retainer and said valve seat member for seating with said slotte-d retainer to prevent iiuid ow from said central bore of said body outwardly through said lateral ports, said spacer member comprising an annular ring having a core of material flowable under predetermined conditions encased within an external flexible covering.

17. A gas lift valve as defined in accordance with claim 16 wherein said body comprises: an articulated structure including upper, central, and lower sections; said upper section and said central section being interconnected by a universal joint including a ring-shaped swivel crosshead, intermeshing upper and lower spider members pivotally connected with said crosshead, said upper spider members being interlocked with said upper body section, said lower spider members being interlocked with said central body section, and said crosshead and spider members being encased within a tubular exible sleeve extending upwardly over a lower end portion of said upper body section and downwardly over upper end portion of said central body section; said lower section of said body being pivotally connected with said central body section by a universal joint including a ring-shaped swivel crosshead, upper and lower intermeshed spider members pivotally assembled on said crosshead, said upper spider members being coupled with a lower end portion of said central body section, said lower spider members being coupled with said lower body section, and said crosshead and spider members being encased within a flexible tubular sleeve, an upper end portion of said sleeve extending over a lower end portion of said central body section and a lower end portion of said sleeve extending over an upper end portion of said lower body section.

18. A gas lift valve as defined in claim 17 including 15 a lower external annular packing supported on said lower body section below said flexible sleeve.

19. A- gas lift valve as defined in claim 18 including an external annular packing supported on said upper body section above the upper end of said exble sleeve.

i 20. A gasl lift valve as dened in claim 16 wherein said core is owable above a predetermined temperature.

21. A gas lift valve as defined in claim 1-6 wherein said core comprises a low melting point metal element.

22. A gas lift valve as defined in claim 16 wherein said core comprises a low melting point metal and said covering comprises rubber wrapped about said core while said core is maintained below its melting point and said spacer is then subjected to heat and pressure thereby 16 binding said rubber together forming an impermeable flexible covering around said core.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 975,826 11/1964 Great Britain.

ALAN COHAN, Primary Examiner. 

1. A WELL TOOL COMPRISING: BODY MEANS HAVING A CENTRAL BORE THERETHROUGH AND LATERAL PORT MEANS COMMUNICATING WITH SAID BORE; VALVE SEAT MEANS SUPPORTED IN SAID BODY MEANS; VALVE MEANS MOVABLY SUPPORTED IN SAID BODY MEANS AND ADAPTED TO COACT WITH SAID SEAT MEANS FOR CONTROLLING FLUID FLOW INTO SAID CENTRAL BORE FROM SAID PORT MEANS, PRESSURE RESPONSIVE MEANS CONNECTED BETWEEN SAID BODY MEANS AND SAID VALVE MEANS FOR MOVABLY SUPPORTING SAID VALVE MEANS WITHIN SAID BODY MEANS, SAID VALVE MEANS INCLUDING SELF-ADJUSTING SPACER MEANS FOR ALIGNING A VALVE SEAT ENGAGING FACE MEMBER OF SAID VALVE MEANS RELATIVE TO SAID VALVE SEAT MEANS, SAID SPACER MEANS INCLUDING A FLOWABLE CORE PORTION AND A COVERING WHEREBY SAID SPACER MEANS IS DEFORMABLE TO JUST THE POSITION OF SAID VALVE SEAT ENGAGING FACE MEMBER TO OBTAIN OPTIMUM ENGAGING RELATIONSHIP BETWEEN SAID FACE MEMBER AND SAID VALVE SEAT MEANS, SAID CORE COMPRISING A LOW MELTING POINT METAL AND SAID COVERING COMPRISES RUBBER WRAPPED ABOUT SAID CORE WHILE SAID CORE IS MAINTAINED BELOW ITS MELTING POINT AND SAID SPACER IS THEN SUBJECTED TO HEAT AND PRESSURE, THEREBY BINDING SAID RUBBER TOGETHER FORMING AN IMPERMEABLE FLEXIBLE COVERING AROUND SAID CORE. 